Take a look at the Bouncing Ball JavaFX example:
https://liveexample.pearsoncmg.com/html/BallPane.htmlLinks to an external site.
https://liveexample.pearsoncmg.com/html/BounceBallControl.htmlLinks to an external site.
Change the program in an Object Oriented way to handle 20 bouncing balls instead of just one.
Notice that for each ball you need:
1. It's center x,y location
2. It's radius
3. It's color
4. It's direction of motion (dx, dy)
Also notice that the JavaFX Circle class already has the information listed in the first 3 items above. So you can create a Ball class that has a Circle in it, PLUS the direction of motion for that ball (dx,dy).
Should it ball have a Move method? or is it best to leave the move method out of the Ball class?